Electric switch



Sept. 30, 1924.

H. l. WASHBURN ELECTRIC SWITCH Filed pril 9. 1921 3 Sheets-Sheet 1 .J m E b N 9 Mb m 6 WM WQ W $\\W\\\\\\\\\\\\\\\ n r all? l I I Sept. 30, 1924. 1,510,122

H. l. WASHBURN ELECTRIC SWITCH Filed April 9, 192] 5 Sheets-Sheet 4 JTTORNEYS.

Sept. 30, 1924.

1. WASHBURN ELECTRIC SWITCH Fil il 1921 3 Sheets-Sheet 5 INVENTOR: flerben j Washimrm ATTORNEYS.

the like.

Fotentetl Sept, 30, 1924,

entree stems her HERBERT 1C.

wesnnorenfon nee-nous. new

Application filled. April 9,

To all whom it may concern:

Be it known that l, HERBERT WestiennN, a. citizen of the United States, resicl ing in Magnolia, in the county 01% Camden and State of New Jersey, have invented certein new and useful Improvements in Electric Switches, whereof the following is specification, reference being had to the so compenying: drawings.

My invention more es .7 o the engineer or pilot, Whether or not apparatus has properly functions t The ohject of my inventioii is the attain merit of utmost simplicity in the construe tion end operation oi switches of thetype referred to, so that they may he cheaply manufactured, and prove absolutely relislole in operation to the exclusion of any possihil ity of becoming deranged in the course long continued usage.

ther objects and attendant advantages of my invention will become apparent, from the detai ed description which follows:

in the drawings, l is e view, portly in plan pertly in section, showing my invention when need as flush Well switch for controlling; electric light circuits and an elevation of the organization gr. l, viewed from the bottom 1 the letter figure, showing, likewise, oerelevation and others in section.

Fig. eteil plain section of the switch pro; or, said section heing taken along: the line Ill-fill in Fig. ll.

" is e, mid-section through the same.

Fig. V is it plain section viewed in the direction of the arrows V-V in Fig. IV.

oe p p t ve ew of relates to electric switche v ished material.

1921. Serial l lo. 45?),2347.

one of the parts of the switch in the :torrn of a block oi insulating material which supports certain of the contact elements.

Fig. V1"; is on end elevation of the switch structure viewed. from the right of P].

Fig. H1 is e detail 1 n section along the line VF VHI 01 Fig. EV showing more particularly, the constrnct o of movable Contact carrying rneinls Fig. 151 is e tregmentiry deteii section through the movable swiw i ing inernher viewed in arrows T l is e (let-W 0 push button of the com nation shown in assemble Fig. is or perspecnv the nietallicolungers which cooperate with the rno ehle contact can switch P llererri EX inclu the moisture preciorotec nve casing switch or en ed has s V .c ed of cast niet rate bottom 2, which, e :r oroperiy been assembled and the necessary electrical connections ma e, is permanently secured oy soldering, Weld ng, in on other approved manner. cs L filled with suitable liquid, as shown TV, which serves not only to lnhrico the movable ports of ,SWlilfili. immersed therein, out also prevents for arcs-between the relatively inc-table contacts of the switch. The liquid may he replenwhen necessary ongh o. screw plugged opening 3, see Fig The top of the casin Q bu b an integral upstanding boss 4 which is morally bored to serve as e hearine for e vertically disposed shaft 5 Which'emends Well into the interior of the casing, and has etteched to its lower end, a movable contact hearing switch ineniher in the form of e coller 8 of insulating ln order to prevent relative rote tion of the collar 6 with to the shaft, the lower end of the letter is flattened, best seen in Figs, 1V and villi, to it e correspondingly shaped aperture in said collar 6. Displacement of the collar is prevented by means of a Washer 7 which may be secured to the shell 5 in any suitable i icrly to Figs. 1 to manner. Recessed in the upper face 01'' the collar 6 are segmental bridging contact plates 8, 8, which are preferably attached to said collar by screws 9, 9 accessible from beneath. The collar 6 has formed in it, radial notches or recesses 10 which underlie the terminal edges of the segmental contact plates 8, 8, and by way of which any metallic particles resulting from wear may gravitate and escape under agitation of the fluid lubricant induced by rotation of the switch.

Surrounding the shaft 5 within the casing 1 is a fixed block of insulating material 11 which is preferably secured to the top of the casing by means of screws 12, 12 which.

. engage within suitable offsets 13, 13 oi the block clearly shown in perspective in Fig. V1. Said block 11 is pierced by a number of apertures 15, 15 which extend longitudinally therethrough, and are disposed symmetrically about the central aperture 16 through which the shaft 5 extends. Slidable within the apertures 15 are a series of plungers 17, 17 which are tubular in form and each constructed preferably of a sheet' metal stamping bent to' the desired shape, as shown in Fig. X1. The lower ends of the plungers 17 are closed by shouldered plugs 18. Said plugs 18 are yieldingly held in engagement with the metallic contact segments 8, 8 of the collar 6 by means of the helical springs 19 which, for the most part, are accommodated within the hollows of the tubular plungers. The upper ends of the springs 19 abut against a disk 20 of insulating material interposed between the block 11 and the top of the casing 1, said' disk thus serving both as a closure for the ends of the apertures 15, and as a means for preventing electrical contact between the ends of the springs 19 and the metal of the casing 1. The plungers 17, 17 are further provided with integral outstanding projections 21 which terminate in eye 22 affording a means of attachment for the ends of electrical connectors 23, 23. The projections 21 of saidplungers 17 pass through slots 25 in the sides of the block 11. Said slots 25 communicate with the respective apertures'15 in a manner clearly shown in Fig. VLand are open at one end of the block 11 sothat the plungers 17 may be readily inserted in assembling the switch. From Figs. TV and V, it will be noted that suilicient slack is allowed in the connectors 23 to permit the free action of the plungers 17, while the opposite ends of said connectors have their source in terminal disks 26 embedded within a molding 27 of insulation, which hermetically seals the opening 28 through which the connectors emerge from the casing 1. The molding 27 is preferably joined with the casing 1 and the terminal disks 26 and portions of connectors 23 embedded in the course oposed at one side and provided with screws 29 whereby the ends of the conductor leads of the circuits which are to be controlled, may be attached to the,switch,suitable in tervening webs 30 integrally formed with the insulation 27 serving to prevent short circuiting between the connections thus made.

When my invention is to be used as a wall switch in electric light circuits, etc., I prefer to use the actuating instrumentalities which are about to be described. To the protruding upper end of the shaft 5 is attached an operating element which, as shown in Fig. 111. is in the form of a tri-arm comprising the extremities 36, 37 and 38. Fixed the limit to which the axis 5 may oscillate.

The extremities 37 and 38 carry, respectively, upstanding lugs or pins 42, 13 which are alternately engaged by hook notches 44c, 441 of the arrow head extremity of a finger 45, in effecting oscillation of the element 35.

The finger 45 is further provided at either side at a point intermediate its length with cam lugs or projections 416, 46, which cooperate in turn with the pins 4-2 and 43 for a purpose which will be later described. Said finger is freely pivoted about a fulcrum stud 47,- depending from. a supporting slide 48 in the term oi a sheet metal stamping which is guided in appropriate ways in bracket arms 49 rising from the casing 1. The slide 48 is shiitable in opposition to a coiled spring 50 spanned between the pin 39 of the element 35 previously referred to, and the depending stud 47 of said slide under pressure applied to a push button 51 mounted upon an integral shank oi the slide. I prefer to mount the push bottom 51 in such manner that it may have capacity for a limited extent. of free motion in opposition to a coiled spring 54 concealed within the hollow of said button as shown in Fig. 1V. At its rear end, the spring 54 abuts against an integral upturned lug 55 ot' the shank 52 of the slide. and the button 51 is held in' assembly with respect to the extension 52 by virtue of engagement of inwardly projecting tabs 56 (see Fig. X) with the inner ends of slots 57 formed in the element 52 (see Fig. TV). The compressive force of the spring 5a is considerintense ably less than the tension of spring 50 so that when the button 51 is pushed inwardly, the spring 54 will he the first to yield.

The switch proper is in turn protected within a suitable metallic housing 60 which isclosed at its front end by a removable plate 61 whereto the casing 1 of the switch is secured. Such attachment is eiiected preferably by stud bolts 62 and'clamp nutsv 63, the exposed ends ofthe bolts at the interior of the casing 1 being covered preferably with solder in the course of manufacture, as to afforda perfect seal in preventing leakage or escape of any of the liquor from the casing. As shown in 'Figs; 1, U and l the push botton 51 is supported for guidance in an opening 64- in the plate 61, and

rotrudes throun'h a clearance ooenin 65 Eli till

in a tlush plate to, which serves tocover the recess inthewall which is to accommodate the housing 60 in accordance with approved practice. The conductors 67 of circuits which are to he controlled the housing? 60 through a pipe 68 secured within an aperture 69 in a manner common to the connection of such electrical appliances,

The operation of t is switch is as follows: Let it be assumed that button 51 has been pushed. and that the element 35 has been thrown by engagement of the pin a3 with the corresponding notch 44 of theiinger 45 so that the pin 39- has been brought against the fixed stop 40'. Upon release of the button, it will be apparent that the spring 50" lmmediately becomes eitective in drawing the slide 48 -forward until its tabs 53 come to a stop against the bracket arms 49 of the casing 1. ln the course of this forward movement the cam lug 46 of the finger 4-5 uppermost in l engages against the pin thus causing the "finger to he swung counter-clockwise about its fulcrum 4-? (Fig. ll'l) so that the opposite notch will he placed into a position to engage the pin 42 to swing the elementfiti in a reverse direction to that of its preceding movement upon the next succeeding depression of the push button 51. Thus in being reciprocated in the interval between the pins 42 and 43., the "finger 45 will cause the alternate throwing of the plate 85 to cneor theothe'r of its positions, cause corresponding movement of the switch in controlling the lights or other appliances in the circuit in which said switch is interposed. It is to he noted that in either final position of the switch, the spring 50 will occupy an angular position to one side or the other of a plane common to the axis 5 of the rotation of the switch and the anchorage pin 47. Furthermore, by reason of the allocation of the pins 39 and 47, respectively at oppositesides of the axis 5 of the switch, the spring 50., after being shifted slightly heyond a dead centre line within the plane above referred to, will become immediately eiiective in bringing about instantaneousimovement of the element 35 in completing the oscillation begun or initiated by movement of the finger 45 in a manner already understood. This instantaneous or snap action promotes both the positive operation of the switch, and also quick separation of the switch contacts, At this time the springo l within the button 51 not only allows the necessary independence of action of the spring 50 as noted, but assists in bringing about the snap action.

l fhile l have shown and described in con nection herewith, a movable switch member with contact segments 8 which serve to hut two of the contact plungers 17 in the immovable block 11, is obvious that both the scope and number of bridging contacts and plungers may be varied in accordance with the functions which the switch form in practice;

now to the embodiment shown tneswitch propen as here represents s precisely the same in construction as tie embodiment first described, but the instrumentalities vby which its op eration is eh ected differ in details which may briefly pointed out as follows:

The housing indicated at 70 is of a somewhat more rugged construction than the housing 6O of the first described form, although of substantially the same design, and has termed integrally with it, a boss 71 which is adapted to align with the axis or sha 5 of the switch asshown. This boss 71 serves as a hearing for an auxiliary shaft 72 having an attached opeuating lever 73 at its outer end by which it may be coordinated with any apparatus whose movements are to be checked under signals controlled by the switch mentioned in the preamble hereto. in order to oloviate the necessity for absolute accuracy in mounting" the switch, ll pre for construct the coupling between the op erating shaft 72 and the shaft 5 oi the switch hy providing the latter with a collar 75 having a tongue or projection which enes within an appropria e bii'urcation iin the lower end of the shaft 72. The operation of the structure shown in l I is thought to be ohviouswithout necessitatingg special description.

The switch proper common to both embodiments of my invention herein described and illustrated, it will be particularly observed is in the course of its manufacture completely assembled with all internal connections made according; to use to which the switch is to' he put. This obviates the necessity for disassembling or dismantling the switch when installations are to he made as required in switches hereto-fore intended for similar purposes.

From the foregoing, it will be readily seen that the simplicity of the switch of my invention, both as to construction and operation, precludes the possibility of derangement in long continued usage, thus obviating the necessity of any attention whatever as to the working mechanism or even with respect to the replenishment of the lubricating liquid. The initial charge of the liquid will last almost indefinitely, since its only possible avenue of escape (by capillarity through the bearing 4t) is rendered substantially liquid tight. by reason of the pressure exerted between the upper face of the bearing 4 and the contacting face of the hub of element 35 under action of the springs 19 which, asis already understood, exert at all times downward pressure on the shaft 15.

Having thus described my invention, ll claim: I

1. Antelectric switch comprising in combination, a closed, dust and moisture-proof, protective casing into which the leads of the conductors of the circuits to be controlled, are passed through a sealed opening; a rotatable shaft extending to the interior of the casing; a movable, contact carrying switch member attached to the shaft within the casing; a fixed block of insulating material wholly contained within the casing adjacent said movable switch member; non-rotatable metallic plungers slidably' disposed in retaining apertures of said block, said plungers being electrically connected with the conductor leads of the controlled circuits; means for yield'ingly maintaining said plungers in engagement with the contacts of the aforesaid movable switch member, and means capable of transportation to angular positions at opposite sides of the rotatable shaft for limiting movement of the switch.

2. An electric switch comprising in combination, a closed, dust and moisture-proof, protective casing into which the leads of the conductors of the circuits to be controlled, are passed through a sealed opening; a rotatable shaft entering the casing at the top and extending well into the interior of the same; a movable, contact carrying, switch member attached tothe inner end of the shaft; an immovable block of insulating material mounted in axial relation about the shaft superj acent. the aforesaid movable switch member and contained wholly within the casing; metallic plungers disposed for non-rotatable guidance in retaining apertures of the block, said plungers being adapted for electrical connection with conductor leads of thecontrolled circuits;

' means for maintaining the plungers positively in yielding engagement with the contacts of the aforesaid movable switch memher, and means capable of transportation to angular positions at opposite sides of the rotatable shaft axis for limiting movement of the switch.

3. An electric switch comprising in comnaioaaa metallic plungers disposed for non-rotatable guidance in retaining apertures of said block, said plungers being closed at one end and adapted for fixed electrical connection with conductor leads of the controlled circuits; an insulating disk interposed between the casing and the block forming a closure for the apertures of the latter at one end; coiled springs for positively maintaining said plungers in engagement with the contacts of the aforesaid movable switch member; said springs being accommodated, for the most part, within the hollows of the plungers and abutting at one end against the aforesaid insulating disk, and spring controlled means capable of transportation to angular positions at opposite sides of the rotative axis of the switch member and thereby limit movement of the switch.

4. An electric switch comprising in combination, a movable, contact carrying, switch member; an immovable block of insulating material located adjacent said movable switch member; metallic plungers guided in retaining apertures in said block, said plung ers being bent, to tubular form, from sheet metal stampings and provided with integral clip extensions adapted to pass throu h appropriate slots in the side of the block to afl ord attachment for the ends of the conductor leads of the circuits which are to be Mill controlled; and coiled springs for positively pressing said plungers into engagement with the contacts of the aforesaid movable switch member.

5. An electric switch comprising in com; bination, a closed, dust and moisture-proof, protective casing; a movable, contact bearing switch member disposed within said casing; an immovable block of insulating material located wholly within the casing adj acent said movable switch member; metallic plungers guided in retaining apertures of said block; means for maintaining said plungers in engagement with the contacts of the movable switch member; flexible eleclit) inflates shaft for said rotary switch member; and instrentalities for oscillating the shaft to shift the switch member, including: an operating element attached to said shaft; stops for limiting the extent of oscillation of said element; a pair of lugs projecting from said element; a :treely pivoted double hooked finger capable of being reciprocated within the interval between said lugs, and swung to position its hooks respectively for alternate engagement with the lugs in the source of successive actuations ot the switch; cam projections on said linger in turn adapted for cooperation with the aforesaid lugs during the retractive movements of the linger in swinging the latter to alternate positions in readiness for engaging the lugs; a slide to which the linger is tulcrumed; and a spring for normally maintaining the slide and linger in retract-ed position Z. An electric switch comprising in combination, a rotary switch member 3 a shaft for sai otary switch member; and instrumentalities for oscillating the shaft to shift the Sm itch member including: an operating element attached to said shaft; stops for limiting the extent of oscillation of the element; a ot' lugs projecting from said element; a freely pivoted, double hooked linger adapted to be reciprocated within the interval between said lugs and swung to position its hooks respectively for alternate engagement with the logs in the course of successive actuations of the switch; cam projections on said finger in turn adapted for cooperation with the aforesaid lugs during the retractive movements of the finger in swinging the latter to alternate positions in readiness for engaging the lugs; a slide to which the linger is tulcrumed; and a helical tension spring attached at one end to the till slide and at the other at aleverage to the aforesaid operating element, said spring being capable of transposition to angular positions at opposite sides of a plane common to its point of anchorage on the slide and the rotative axis oi the switch, so that the element is normally yieldingly held against one or the other of its limiting stops, and the slide at same time held normally retracted position. v 8. An electric switch comprising in combination a rotary switch member; a control shaft for said switch rotary member; and instrumentalities for oscillating the shaft to shift the rotary switch member including: a tri-arm operating element attached to said shalt; tired stops for limiting oscillation of said element; actuating means including a slidable member for initiating shitting of said tri-arm element into engagement with one or the other of said stops; 'an arrowheaded linger fulcrumed to said slidable member; and a helical tension spring attached at one end to said tri-arm clement at a leverage distance to oneside of the axis the direction initiated by the action of the actuating means.

9. electric switch comprising in combination a rotary switch member; control shaft for said switch rotary member; and instrunientalities for oscillating the shaft to shift the rotary switch member including: a tri-arm element attached to said shaft: fixed st ps for limiting oscillation oi said element; a slide capable of limited movement h :ving an arrow-headed linger fulcrumed thereto for initiating shifting of said element into engagement with one or the other of said stops; a helical tension spring attached at one end to the tri-arm element at a leverage distance to one side of the axis of rotation of the switch, and at the other end to the fulcrum of the aforesaid finger so that when the tri-arm element is shifted ineither direction to bring the centre of attachment of the spring to a position slightly beyond a dead centre line, said spring becomes automatically effective in bringing about instantaneous completion of the movement ofthe switch element in the direction initiated by the action of the actuating means; and a push button attached to the slide with capacity for independent motion in permitting the instantaneous movement of the switch element as aforesaid.

10. An electric switch comprising in combination, a rotary switch member; a control shaft for said switch rotary member; and instrumentalities for oscillating the shaft to shift rotary switch member including: a tri-arm attached to said shalt; fixed stops for limiting oscillation of said tri-arm; a slide capable of limited movement having an arrow-headed finger fulcrumed thereto for initiating shifting of the tri-arm into engagement with one or the other of said stops; a helical tension spring attached at one end to the tri-arm at a leverage distance to one side of the axis of rotation of the switch and at the other end to the fulcrum ot the aforesaid finger, so that when the element is shitted in either direction to bring the centre or attachment of the spring to a position slightly beyond a dead centre line,

said spring becomes automatically efiective i in bringing about instantaneous completion of the movement of the switch in the direction initiated by the action of the slide and an associate push button, said button being subject to an opposing spring adapted to Elm W lating material; and a movable contact supporting member also of insulating material,

the metallic contacts of one of said elements being maintained in frictional engagement with spaced metallic bridging segments on the other, and the latter provided, beneath the terminal edges of the'segments, with grooves by 'Way of Which metallic particles resulting from the Wear of the contact elements are carried off under motion of the liquid lubricant induced during the operation of the switch.

In testimony whereof, l have hereunto signed my name at Philadelphia, Pennsyl- Vania, this 7th day of April, 1921.

HERBERT l. l/VASHBUEN. Witnesses:

James H. BELL, E. L. FULLERTON. 

